On this Mint 17.2 Cinnamon 32 bit system, the Arduino IDE (1.8.5) does not seem to want to recognise any symlinks as valid serial ports either. It does however recognise /dev/ttyUSB0 etc, so long as that is not a symlink.

I can now reacquaint myself with the Tsunami, after over a year away, and "converting" from Windows to Linux. Maybe I can make it work as a passive component bridge. Lots to learn yet.